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Experimental Study of the Deformation of Instantaneous Neutron Spectra from the Fission of 235U Nuclei in Fast-Reactor Core Materials

“…(5) In neutron fields nos. 5,7,9,11, and 12, an additional slight deformation of the initial spectrum of the instantaneous fission neutrons is observed near the reactor cores due to the contribution to the spectrum from the neutrons scattered by the core's surroundings (the walls, floor, and ceiling of the reactor chamber).…”

“…In addition, the regions of sensitivity to neutrons inside the detectors used in spectral measurements must span the energy range of the measured spectrum [11]. The systemic error in reconstructing the neutron spectrum is determined by the physical accuracy of forming the a priori neutron spectrum: the closer this spectrum is to the spectrum under study, the more exact the reconstructed spectrum will be in the reactor field under investigation.…”

“…The cross section of inelastic neutron scattering by Mo nuclei becomes substantial only at a neutron energy of >1 MeV. The cross sections of elastic neutron scattering by C (contained in the BIGR-reactor core) and H nuclei (in the converter of the GIR-2 reactor) are quite large (5 and 20 b, respectively) and remain constant up to energies of 10 4 -10 5 eV [8,11,12].…”

Study of Neutron Spectra Near the Surfaces of Iron and Water Spheres with 252Cf Sources at Their Centers

“…In addition, the regions of sensitivity to neutrons for the detectors used to measure the spectrum must span the entire energy range of this spectrum [21]. A sufficient condition for correctly measuring the spectra in the neutron fields under study by the neutron-activation method is the formation of physically substantiated a priori spectra for them.…”

Studying Neutron Spectra at the Centers of the Metal Cores of Fast Research Reactors

“…The neutron energy spectra (hereafter, spectra) at the metal-core centers of fast reactors were measured by the neutron activation method using the standardized detectors and techniques in [3].…”